AOR Vitamin C - 300 V-Caps

The History of Vitamin C

We have all heard of Vitamin C. Yet how many of us truly know what it is? Vitamin C, a.k.a. Ascorbic Acid, is the antiscorbutic vitamin. Although scurvy was first described during the Crusades and commonly plagued early explorers and voyagers, the specific relationship between scurvy, citrus foods, and ascorbic acid was not established until the 20th century.

English sailors have been nicknamed "limeys" since the days when the Queen's ships were required to carry citrus fruits (mainly lemons) as scurvy preventatives. For practical purposes, the examination of vitamin C needs to begin in 1937, and the name Albert Imre Szent-Gyorgyi (1893-1986), a Hungarian-born biochemist, is the most prominent name by far when it comes to vitamin C. Szent-Gyorgyi isolated this vitamin in 1937, winning the Nobel Prize for Medicine in that same year. His research on biological oxidation provided the basis for Krebs' citric acid cycle. Curiously, nearly all species of mammals can synthesize their own vitamin C endogenously. The few interesting exceptions are primates, guinea pigs, and a handful of exotic curiosities such as the Indian fruit bat.

What Can It Do And How Does It Do It?
Unlike other water-soluble vitamins, vitamin C, or ascorbic acid, doesn't appear to act either as a catalyst or as a coenzyme. Most people think of it primarily as an antioxidant - which it is, and a crucial one at that. It can scavenge both reactive oxygen species and reactive nitrogen species. By virtue of this scavenging activity, ascorbic acid inhibits lipid peroxidation, oxidative DNA damage and oxidative protein damage. In this renowned function as an antioxidant, ascorbic acid seems especially prominent as a protector of lipids and lipid-based nutrients. It directly protects such fat-soluble vitamins like vitamin A and vitamin E, not to mention various fatty acids from the damage caused by the excessive oxidation of free radicals. Ascorbic acid is oxidized by reactive oxygen and nitrogen species to the semidehydroascorbate radical. The semidehydroascorbate radical is either reconverted to ascorbate via the enzyme NADH semidehydroascorbate reductase or is converted to dehydroascorbate. Dehydroascorbate in turn can be converted back to ascorbate via glutathione-dependent enzymes or catabolized. As per glutathione, ascorbic acid helps preserve reduced intracellular glutathione concentrations. This activity likely helps maintain nitric oxide levels and potentiates its vasoactive effects. Oral ascorbic acid can reach high enough concentrations to scavenge superoxide radicals. Therefore, intracellular sources of superoxide that impair nitric oxide may be scavenged by oral ascorbic acid.

Research suggests ...
There is a fair amount of depth to the ascorbic acid research, most of it on the preventative aspect. Such preventative effects may be accounted for, in part, by ascorbic acid's ability to detoxify carcinogens directly, as well as blocking carcinogenic processes via its antioxidant activity. Vitamin C can prevent the formation of such carcinogens as nitrosamines in foods and in the gastrointestinal tract. It can also detoxify such chemical mutagens and carcinogens as anthracene, benzo[a]pyrene, organochlorine pesticides and heavy metals. High concentrations of ascorbic acid in gastric juice may reduce the risk of unhealthy gastric cells by inhibiting the formation of carcinogenic N-nitroso compounds. Additionally, increased oxidative stress to the gastric mucosa has been reported in Helicobacter pylori-associated gastritis. There is preliminary evidence suggesting that vitamin C can inhibit the growth of Helicobacter pylori.

Hypertension and Hypercholesterolemia
For those suffering from hypertension, there is an indication that ascorbic acid may improve endothelial-dependent vasodilation. That indication is likewise evident in those with hypercholesterolemia as well, and ascorbic acid may also help restore nitric oxide-mediated flow-dependent vasodilation in those with congestive heart failure.

Immune System
The well-worn association between vitamin C and the common cold may be explained by the anti-histamine effects of the vitamin. These same effects also reduce the immunosuppressive activity of histamine, thus enhancing neutrophilic chemotaxis, giving ascorbic acid an overall immunomodulatory role as well.